The present invention relates to an immunostimulant agent, and more particularly to a clinically applicable immunostimulant agent containing interleukin-2 (hereinafter also briefly referred to as IL-2) and 5'-deoxy-5-fluorouridine (generic name: doxifluridine, hereinafter also briefly referred to as 5'-DFUR).
Attempts have been made in recent years, as immunostimulant agent and various viral infections, by using the so-called lymphokines such as IL-2 for immunopotentiation [J. Immunol., 125, 1904 (1980)]. Recently, IL-2 obtained by genetic engineering technique has been known (Japanese Patent Unexamined Publication Nos. 60-115528/1985 and 61-78799/1986).
On the other hand, 5'-DFUR was synthesized in 1979, and the effectiveness thereof in clinical tests was discovered [Cancer and Chemotherapy 12(1), 2044 (1985)]. For this reason, 5'-DFUR has recently been on the market.
At present, cancer has been tried to be treated by operative therapy, radiotherapy and hormonotherapy, which are effective against primary cancer. However, metastasized cancer and too late discovered cancer cannot be so treated, therefore, pharmacotherapy is used. Anticancer drugs currently usable exhibit a useful effect, but have strong side effects on organisms. Pharmacotherapy is not completely satisfactory as therapy for patients.
In recent years, lymphokines such as IL-2 have been used as antitumor agents to treat human malignant tumors [Cancer and Chemotherapy 13, 977 (1986)], and therapeutic effects thereof have also been reported [New England J. Med. 316, 889 (1987)].